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/* BZ #18877, BZ #21270, and BZ #24699 mmap offset test.
Copyright (C) 2015-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/mman.h>
#include <mmap_info.h>
#include <support/check.h>
static int fd;
static long int page_shift;
static char fname[] = "/tmp/tst-mmap-offset-XXXXXX";
static void
do_prepare (int argc, char **argv)
{
fd = mkstemp64 (fname);
if (fd < 0)
FAIL_EXIT1 ("mkstemp failed");
if (unlink (fname))
FAIL_EXIT1 ("unlink failed");
long sz = sysconf(_SC_PAGESIZE);
if (sz == -1)
sz = 4096L;
page_shift = ffs (sz) - 1;
}
#define PREPARE do_prepare
/* Check if negative offsets are handled correctly by mmap. */
static int
do_test_bz18877 (void)
{
const int prot = PROT_READ | PROT_WRITE;
const int flags = MAP_SHARED;
const unsigned long length = 0x10000;
const unsigned long offset = 0xace00000;
const unsigned long size = offset + length;
void *addr;
if (ftruncate64 (fd, size))
FAIL_RET ("ftruncate64 failed");
addr = mmap (NULL, length, prot, flags, fd, offset);
if (MAP_FAILED == addr)
FAIL_RET ("mmap failed");
/* This memcpy is likely to SIGBUS if mmap has messed up with offset. */
memcpy (addr, fname, sizeof (fname));
return 0;
}
/* Check if invalid offset are handled correctly by mmap. */
static int
do_test_large_offset (void)
{
/* For architectures with sizeof (off_t) < sizeof (off64_t) mmap is
implemented with __SYS_mmap2 syscall and the offset is represented in
multiples of page size. For offset larger than
'1 << (page_shift + 8 * sizeof (off_t))' (that is, 1<<44 on system with
page size of 4096 bytes) the system call silently truncates the offset.
For this case glibc mmap implementation returns EINVAL. */
const int prot = PROT_READ | PROT_WRITE;
const int flags = MAP_SHARED;
const int64_t offset = 1ULL << (page_shift + 8 * sizeof (uint32_t));
const size_t length = 4096;
void *addr = mmap64 (NULL, length, prot, flags, fd, offset);
if (mmap64_maximum_offset (page_shift) < UINT64_MAX)
{
if ((addr != MAP_FAILED) && (errno != EINVAL))
FAIL_RET ("mmap succeed");
}
else
{
if (addr == MAP_FAILED)
FAIL_RET ("mmap failed");
}
return 0;
}
int
do_test (void)
{
int ret = 0;
ret += do_test_bz18877 ();
ret += do_test_large_offset ();
return ret;
}
#include <support/test-driver.c>
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